Did a little more checking on this.
It seems that there is problem with the process to populate table jbp_cms_repositoryentry initially. The fsentry_length shows a size of 2270 while the fsentry_data is null.
I am using Oracle 9i
I was able to bypass the problem by configuring to use file system for repository instead of using DB
I'm having the same problem. I submitted a bug to JBoss JIRA: JBPORTAL-816